PIPE

For an isometric process involving 3 kg of air, the temperature increases from 20°C to 100°C. Calculate the heat added (Cv=0.718 kJ/kg-K).

172.3 kJ

In an isobaric process, 2 m3 of gas at 200 kPa is compressed to 1 m3. Calculate the work done.

-200 kJ

Air is compressed isothermally from 100 kPa and 0.5 m3 to 500 kPa. What is the final volume?

0.1 m³

Calculate the work done during the isothermal compression in Question 63.

-80.5 kJ

A gas undergoes an isentropic expansion where P1 =600 kPa, V1=0.1 m3, and V2=0.3 m3. If k=1.4, find the final pressure.

128.9 kPa

Calculate the work done in the isentropic process in Question 65.

64.8 kJ

A polytropic process (n=1.3) expands a gas from 500 kPa and 0.2 m3 to 100 kPa. What is the final volume?

0.689 m³

In an isometric process, the work done is always:

Zero

For an ideal gas, the change in internal energy (ΔU) during an isothermal process is:

Zero

Which process is also known as "isopiestic"?

Isobaric

A gas is compressed in a polytropic process (n=1.2) from 100 kPa and 25°C to 400 kPa. Find the final temperature.

100°C

For an isentropic process, the heat transfer Q is:

Zero

Calculate the change in entropy (ΔS) for 1 kg of air heated at constant volume from 300 K to 600 K.

0.498 kJ/K

A piston-cylinder moves 2 kg of air isobarically at 300 kPa from 40°C to 150°C. Calculate the work.

63.1 kJ

Find the polytropic specific heat Cn if Cv=0.718, k=1.4, and n=1.2.

-0.718 kJ/kg-K

In a throttling process, which property remains constant?

Enthalpy

An isentropic process is both:

Adiabatic and reversible

If 100 kJ of work is done ON a gas during an isothermal process, the heat transfer is:

100 kJ rejected

The ratio of Cp to Cv is called:

Specific heat ratio

Calculate the change in enthalpy for 2 kg of air (Cp=1.006) when heated from 20°C to 120°C.

201.2 kJ

When gas is heated at constant pressure, the process is called

isobaric

A group of 50 persons attend a secret meeting in a room which is 12 meters wide by 10 meters long and a ceiling height of 3 m. The room is completely sealed off and insulated. Each person gives off 120 kcal per hour of heat and occupies a volume of 0.2 m3. The room has an initial pressure of 101.3 kpa and temperature of 16oC. Calculate the room temperature after 10 minutes.

33.10

In a Diesel cycle, the compression ratio is 15. Compression begins at 0.1 Mpa, 40°C. The heat added is 1.675 MJ/kg. Find the MEP of the cycle.

1131. 4 Kpa

Consider two Carnot heat engines operating in series. The first engine receives heat from the reservoir at 2500K and rejects the waste heat to another reservoir at temperature T. The second engine receives heat by the first one, convert some of it to work, and rejects the rest to a reservoir at 300K. If thermal efficiencies of both engines are the same, determine the temperature T.

849 K

In an ideal Brayton cycle has a net work output of 150 KJ/kg and backwork ratio of 0.4. If both the turbine and the compressor had an isentropic efficiency of 80%, the net work output of the cycle would be.

75 KJ/kg

A water reservoir contains 100,000 kg of water at an average elevation of 60 m. The maximum amount of electric power that can be generated from this water is:

16 KWh

The gain of entropy during isothermal nonflow process of 5 lb of air at 60℉ is 0.462 Btu/R. Find the V1/V2.

0.259

An auditorium seating 1500 people is to be maintained at 80℉ dry bulb and 85℉ wet bulb temperature when outdoor air is at 91℉ dry bulb and 75℉ wet bulb. Solar heat load is 110,000 Btu/hr and supply air at 60℉, determine the amount of supply air. Sensible heat per person = 225 Btu/hr

93,229.17 lb/hr

In a Brayton cycle that operates between temperature limits of 300K and 1773K wit k = 1.4, determine the temperature at the end of the compression (isentropic) for maximum work of the cycle.

730K

Work done by a substance in reversible non flow manner in accordance with V = 100/P ft3, where P is in psia. Evaluate the work done on or by the substance as the pressure increases from 10 psia to 100 psia.

-33,157.22 ft-lb

A cylindrical flash tank mounted with its axis horizontal is used to separate liquid ammonia from ammonia vapor. The ammonia vapor bubbles through the liquid with 70 m3/min leaving the disengaging surface. The disengaging rate is limited to 60 m/min and the liquid level is to operate with the liquid level one-third of the diameter from the top. Determine the diameter if the tank is 1.5 m long.

830 mm

A 150 Hp motor is used to drive a compressor. If the heat loss from the compressor is 25 kW and the mass flow rate of the refrigerant entering the compressor is 0.50 kg/s, determine the difference of the enthalpies between the inlet and outlet of the compressor.

173.80 kJ/kg

Find the pressure at the 100 fathom depth of water in kpag.

1,793.96 kpag

Find the work possess for a Helium gas at 200C

609 KJ/kg

Two kilogram of gas is confined in a 1 m3 tank at 200 kpa and 88°C. What type of gas is in the tank?

Ethane

Find the enthalpy of Helium if its internal energy is 200 KJ/kg

333.42 kJ/kg

Compute the mass of a 2 m3 propane at 280 kpa and 40˚C.

9.47 kg

At the beginning of the compression stroke of an ideal Otto Cycle has an air pressure of 15 psia, a temperature of 75oF and a specific volume of 13.2 ft3/lb. At the end of compression, the specific volume is 1.76 ft3/lb. The heat supplied to the cycle is 352 Btu/lb. Calculate the highest pressure of the cycle.

685 psia

For steam power plants, decreasing the operating pressure of the boiler will

decrease thermal efficiency

Carnot cycle A, B and C are connected in series so that the heat rejected from A will be the heat added to B and heat rejected from B will be added to C, each cycle operates between 30 ˚C and 400 ˚C. If heat added to A is 1000 kw, find the work output of C.

111.44 kw

A 0.5 m3 tank contains Nitrogen at 200 kPa and 30°C. Calculate the mass of the gas

1.11 kg

Water flows through a pipe with a velocity of 3 m/s. If the pipe diameter is 10 cm, what is the volume flow rate?

0.0236 m³/s

Air at 500 kPa and 100°C occupies a volume of 2 m3. If the volume is halved while the temperature remains constant, what is the new pressure?

1000 kPa

A nozzle has an inlet area of 0.02 m2 and an exit area of 0.005 m2. If the inlet velocity is 10 m/s, what is the exit velocity for an incompressible fluid?

40 m/s

Calculate the mass flow rate of oil (ρ=850 kg/m3) flowing at 2 m/s through a 50 mm diameter pipe.

3.34 kg/s

A gas at 100 psia and 80°F is compressed to 400 psia. If the process is isochoric, what is the final temperature in °F?

1700 °F

Find the gas constant R for a gas with a molecular weight of 44 kg/kmol.

0.189 kJ/kg-K

A balloon is filled with 10000 liters of Helium at 101.3 kPa and 59°F. What is the mass of Helium?

1.69 kg

Oxygen at 25°C and 1 atm occupies 5 liters. If the pressure is increased to 3 atm and the temperature to 100°C, what is the new volume?

2.09 L

Determine the density of Air at 2.96 atm and 122°F.

3.23 kg/m³

A new temperature scale, the "Z-scale," marks the freezing point of water at -20°Z and the boiling point at 180°Z. If a substance is at 50°C, what is its temperature in °Z?

80°Z

Determine the absolute temperature in Rankine for a substance at 45°C.

572.4 °R

At what temperature do the Fahrenheit and Celsius scales provide the same numerical reading?

-40°

A cooling system lowers the temperature of a coolant by 35°C. What is this temperature change in Fahrenheit degrees?

63°F

Which of the following is an extensive property?

Total Enthalpy

An object has a mass of 15 kg on Earth. What is its weight on the moon where g=1.62 m/s2?

24.3 N

Convert a pressure of 450 mm Hg to kilopascals (kPa).

59.99 kPa

A pressure gauge reads 250 kPa in a location where the atmospheric pressure is 98 kPa. Calculate the absolute pressure.

348 kPa

If the specific gravity of an oil is 0.82, what is its density in lb/ft3?

51.17 lb/ft³

A vacuum gauge connected to a chamber reads 35 kPa. If the local barometric pressure is 100 kPa, what is the absolute pressure?

65 kPa

Calculate the specific volume of a gas if its density is 1.25 kg/m3.

0.8 m³/kg

A 5-slug mass is accelerated at 10 ft/s2. What is the force required in lbf?

50 lb_f

How many liters are in 5.5 cubic meters (m³)?

5,500 L

A tank contains 250 gallons of water. What is the mass of the water in kilograms? (Assume density = 1000 kg/m3)

946 kg

Find the temperature in Kelvin if the reading is 120°F.

322 K

Which law states that if two systems are in thermal equilibrium with a third, they are in equilibrium with each other?

Zeroth Law

A force of 500 N is applied over an area of 0.05 m2. What is the pressure in bar?

0.1 bar

If a fluid has a specific weight of 9.5 kN/m3, what is its density?

968.4 kg/m³

In the English system, the universal gas constant R is equal to:

Both A and C

A property that is independent of the mass of the system is called:

Intensive

A compressor handles 500 m3/hr of air at 100 kPa and 20°C. What is the mass flow rate in kg/s?

0.165 kg/s

If a gas has k=1.3 and R=0.26 kJ/kg-K, find Cv.

0.867 kJ/kg-K

If a gas has k=1.3 and R=0.26 kJ/kg-K, find Cv.

Calculate Cp for the gas in the previous question.

1.127 kJ/kg-K

A 10 lb mass of air (R=53.3 ft-lb/lb-°R) is at 100 psia and 500°R. What is its volume?

18.5 ft³

The mass flow rate of a fluid is 5 kg/s. If the density is 800 kg/m3, what is the volume flow rate?

0.00625 m³/s

A piston-cylinder contains 2 kg of air at 200 kPa. If the volume is 0.8 m3, what is the temperature?

278.7 K

A gas is heated from 30°C to 150°C at constant pressure. If the initial volume was 2 m3, what is the final volume?

2.79 m³

Calculate the number of moles in 10 kg of CO2 (MW=44).

0.227 kmol

Air flows through a square duct (0.5m x 0.5m) at 5 m/s. What is the volume flow rate?

1.25 m³/s

If the pressure of a gas is doubled and the absolute temperature is tripled, the volume will:

Increase by 1.5 times

A 50 kg block is raised 20 meters. Calculate the change in potential energy (g=9.81 m/s2).

9.81 kJ

A car of mass 1200 kg moves at 25 m/s. What is its kinetic energy?

375 kJ

500 kJ of heat is added to a system while it performs 200 kJ of work. What is the change in internal energy?

300 kJ

A closed system undergoes a process where the internal energy decreases by 150 kJ and 50 kJ of work is done ON the system. Find the heat transfer.

200 kJ rejected

How much heat is required to raise the temperature of 5 kg of water from 20°C to 80°C (Cp=4.187 kJ/kg-K)?

1256 kJ

Calculate the work done by a gas expanding from 1 m3 to 3 m3 at a constant pressure of 150 kPa.

300 kJ

A 2 kW electric heater runs for 30 minutes. How much energy is delivered in kJ?

3600 kJ

Find the enthalpy of a system if the internal energy is 250 kJ, pressure is 100 kPa, and volume is 0.5 m3.

300 kJ

How much power is required to lift a 200 kg load at a constant speed of 2 m/s?

3.92 kW

2 kg of ice at 0°C melts into water at 0°C. If the latent heat of fusion is 335 kJ/kg, how much heat was added?

670 kJ

A turbine produces 5000 kJ of work while 1000 kJ of heat is lost to the surroundings. What is the change in enthalpy (neglecting KE and PE)?

-6000 kJ

Calculate the flow work for a fluid entering a system at 500 kPa with a specific volume of 0.2 m3/kg.

100 kJ/kg

A 0.5 hp motor is used to drive a pump. Convert this power to Watts.

373 W

The specific heat of a metal is 0.9 kJ/kg-K. If 180 kJ of heat is added to a 10 kg block, what is the temperature rise?

20°C

If the work done on a compressor is 150 kJ/kg and the heat rejected is 40 kJ/kg, what is the change in enthalpy (neglect KE/PE)?

110 kJ/kg

A heat engine receives 1000 kJ of heat and rejects 600 kJ. What is its efficiency?

40%

Calculate the kinetic energy of air flowing at 100 m/s per kg of air.

5 kJ/kg

10 kg of steam has an enthalpy of 2800 kJ/kg. What is the total enthalpy?

28,000 kJ

A process is adiabatic if:

Heat transfer is zero

Work done during a process is 450 ft-lb. Convert this to Btu (1 Btu=778 ft-lb).

0.578 Btu